Wireless local area WLAN networks (WLAN) have seen exponential growth across organizations in many industries. High-density wireless networks are increasingly in demand. Many new technologies have been adopted, such as multi-user multiple input multiple output (MU-MIMO) technology. As compared to single-user MIMO (SU-MIMO), MU-MIMO has several key advantages. First, MU-MIMO allows for a direct gain in multiple access system capacity proportional to the number of access point antennas. Second, MU-MIMO allows the higher degree spatial multiplexing gain to be obtained without the need for a higher number of antennas at the mobile stations by keeping the intelligence and cost at the access point. Third, MU-MIMO appears immune to most propagation limitations plaguing SU-MIMO communications because multiuser diversity can be extracted even in a simple line of sight (LOS) propagation environment. As a result, the LOS propagation, which causes degradation in single user spatial multiplexing schemes, is no longer a problem in the multiuser setting. The amount of data transmitted over the Internet has been growing exponentially. Further, with the rapid development of the technology, wireless connections will not only connect people via voice and data communications but also will connect smart devices, also called Internet of Things (IoT). The number of devices connected through wireless communication demands higher efficiency of the wireless network. Consequently, MU-MIMO becomes more widely adopted.
Currently, for wideband WLANWLAN downlink and uplink channels, a single user occupies the whole wideband. The signaling field for a user occupies a portion of the wideband. Therefore, with a single user occupying the wideband channel, the signaling fields of such wideband channels are duplicated resulting in degradation in bandwidth efficiency. With the growing demands for capacity of the WLANWLAN network, sharing the wideband with multiple users are desired.
Orthogonal frequency division multiple access (OFDMA) technology is developed in the cellular network enabling multiple users sharing the same wideband at the same time. Such technology, however, is not developed for the WLANWLAN network. How to adapt the OFDMA technology to the WLANWLAN to enable multiple users sharing the same wideband remains a question.
To improve the efficiency of the WLANWLAN network allowing multiple users to share the same wideband WLANWLAN channel, improvement and enhancement are required for the WLANWLAN network.